There are many applications for horizontal sliding doors wherein it is necessary to provide a tight sealing action between the door and the walls surrounding the opening that the door closes. In order to provide for such tight sealing action while preventing sliding friction between the door or wall and the sealing means (with subsequent quick degradation of the sealing elements), many conventional horizontal sliding doors utilize mechanisms for moving the door inwardly (toward the wall) and downwardly at the end of travel during the door closing action. This avoids frictional action on the sealing elements during the sliding action, but causes compression of the sealing elements between the door and wall upon final closing. Typical prior art arrangements for effecting this sealing action are shown in U.S. Pat. Nos. 3,276,166; 3,611,637; and 4,404,770.
According to the present invention, a sliding door assembly is provided which includes the desirable inward and downward movement of the door at the end of its horizontal path of movement in order to effect proper sealing, and the assembly according to the present invention accomplishes this desired result in a simple and advantageous manner. The assembly according to the present invention accomplishes the desired sealing action utilizing only two rollers for mounting the door on a track attached to the wall above the door. The two rollers are disposed within the projection of the width of the door, minimizing the size of the track, mounting, and like components.
The door assembly according to the present invention includes track means having first and second intersecting surfaces, the surfaces elongated in the horizontal direction of sliding of the door. The rollers, which are preferably V-shaped, have first and second surfaces thereof which cooperate with the first and second surfaces of the track. First and second contoured ramps are formed in the track. The first ramp is formed at the very leading edge of the track, and the second ramp is formed in the track at a distance spaced from the first ramp the same distance that the rollers are spaced from each other. At the second ramp a bridge is provided which provides a continuation of the first surface at the second ramp. The first and second ramps continuously move downwardly and inwardly while extending in the direction of horizontal sliding, so that when the rollers follow the ramp the desired end-of-travel sealing action results.
The leading roller has a longer first surface than the length of the first surface of the trailing roller. This means that when the leading roller approaches the second contoured ramp, the first surface thereof engages the bridge so that the leading roller does not follow the second contoured ramp. However the second roller, when it approaches the second contoured ramp, does not engage the bridge, so that it does follow the second contoured ramp (at the same time that the leading roller is following the first contoured ramp) so that the end of travel sealing action occurs.
It is the primary object of the present invention to provide a simple and effective sliding door assembly for closing an opening in a wall. This and other objects of the invention will become clear from an inspection of the detailed description of the invention, and from the appended claims.